The present invention relates to a control method for a link arm mechanism which is preferably used as a handling mechanism for shifting a test specimen. Furthermore, the present invention relates to a centrifugal operation system comprising an automatic centrifugal machine and an associated conveyor line. The automatic centrifugal machine employs the link arm mechanism for transporting the test specimen from the conveyor line to a rotor to perform a centrifugal separation.
Unexamined Japanese patent application No. 58-160071 discloses a conventional link arm mechanism comprising a shift member (i.e., a mechanical hand) supported by two sliders shiftable in parallel with each other.